Field of the Invention
The present invention relates to a magnetic resonance (MR) signal receiving apparatus, a reception coil channel selector, and a magnetic resonance imaging (MRI) system.
Description of the Prior Art
At present, in order to acquire a full-body (MR) image, a total imaging matrix (TIM) has the largest coverage, the highest signal-to-noise ratio and the highest speed. Multiple antenna unit coils must be used in a TIM. During a scan, a user generally connects to the system the coils which he or she needs to simultaneously use, and selects from the coils a specific combination of a portion of the antenna units for a specific region under examination, and so does not need to change coils and reposition the patient during the scan. Thus, it is necessary to be able to connect a specific antenna unit within a desired coil to a radio frequency (RF) receiver arbitrarily.
FIG. 6 shows as an example a magnetic resonance signal reception link of an existing local coil. In FIG. 6, one local coil 40 has M antenna units (coil elements) 41, each antenna unit 41 having its own amplifier 42 and its own cable. Thus, M cables must be configured for each local coil 40; the volume and quantity of cables are high, and apart from being expensive to manufacture, the cables are not very comfortable. In addition, magnetic resonance signals from the antenna units 41 pass through a reception coil channel selector (RCCS) 50 and enter an RF receiver 60. The RCCS 50 is a switch array with L*M input terminals and N output terminals. Specifically, magnetic resonance signals of L*M antenna units 41 are switched to N output channels via the RCCS 50. In turn, the N output channels of the RCCS 50 are connected to N receiving channels of the RF receiver 60. In addition, the RF receiver 60 comprises an amplifier 61, a compressor 62, an analog-to-digital converter (ADC) 63 and a digital processor 64.
Hence, in the existing technical solution described above, M cables must be provided for each local coil, and each receiver 60 must further be provided with N receiving channels, so the costs of the cables and receiver are high. Moreover, in such an existing magnetic resonance signal receiving link, wastage of output channels of the RCCS 50 or receiving channels of the RF receiver 60 will sometimes result. In particular, when an MRI apparatus has multiple local coils, the increase in these costs is more obvious.